PSCI: Do psci_setup() as part of std_svc_setup()

This patch moves the invocation of `psci_setup()` from BL31 and SP_MIN
into `std_svc_setup()` as part of ARM Standard Service initialization.
This allows us to consolidate ARM Standard Service initializations which
will be added to in the future. A new function `get_arm_std_svc_args()`
is introduced to get arguments corresponding to each standard service.
This function must be implemented by the EL3 Runtime Firmware and both
SP_MIN and BL31 implement it.

Change-Id: I38e1b644f797fa4089b20574bd4a10f0419de184

4 files changed, 58 insertions, 24 deletions

diff --git a/bl31/bl31_main.c b/bl31/bl31_main.c
index 7b0b675b..fae5ee4e 100644
--- a/bl31/bl31_main.c
+++ b/bl31/bl31_main.c
@@ -53,21 +53,27 @@ static int32_t (*bl32_init)(void);
  ******************************************************************************/
 static uint32_t next_image_type = NON_SECURE;
 
+/*
+ * Implement the ARM Standard Service function to get arguments for a
+ * particular service.
+ */
+uintptr_t get_arm_std_svc_args(unsigned int svc_mask)
+{
+	/* Setup the arguments for PSCI Library */
+	DEFINE_STATIC_PSCI_LIB_ARGS_V1(psci_args, bl31_warm_entrypoint);
+
+	/* PSCI is the only ARM Standard Service implemented */
+	assert(svc_mask == PSCI_FID_MASK);
+
+	return (uintptr_t)&psci_args;
+}
+
 /*******************************************************************************
  * Simple function to initialise all BL31 helper libraries.
  ******************************************************************************/
 void bl31_lib_init(void)
 {
-	/* Setup the arguments for PSCI Library */
-	DEFINE_STATIC_PSCI_LIB_ARGS_V1(psci_args, bl31_warm_entrypoint);
-
 	cm_init();
-
-	/*
-	 * Initialize the PSCI library here. This also does EL3 architectural
-	 * setup.
-	 */
-	psci_setup(&psci_args);
 }
 
 /*******************************************************************************
@@ -89,7 +95,7 @@ void bl31_main(void)
 	/* Initialise helper libraries */
 	bl31_lib_init();
 
-	/* Initialize the runtime services e.g. psci */
+	/* Initialize the runtime services e.g. psci. */
 	INFO("BL31: Initializing runtime services\n");
 	runtime_svc_init();
 
diff --git a/bl32/sp_min/sp_min_main.c b/bl32/sp_min/sp_min_main.c
index c1ba8fc5..02663a29 100644
--- a/bl32/sp_min/sp_min_main.c
+++ b/bl32/sp_min/sp_min_main.c
@@ -151,30 +151,33 @@ static void sp_min_prepare_next_image_entry(void)
 }
 
 /******************************************************************************
- * The SP_MIN main function. Do the platform and PSCI Library setup. Also
- * initialize the runtime service framework.
+ * Implement the ARM Standard Service function to get arguments for a
+ * particular service.
  *****************************************************************************/
-void sp_min_main(void)
+uintptr_t get_arm_std_svc_args(unsigned int svc_mask)
 {
 	/* Setup the arguments for PSCI Library */
 	DEFINE_STATIC_PSCI_LIB_ARGS_V1(psci_args, sp_min_warm_entrypoint);
 
+	/* PSCI is the only ARM Standard Service implemented */
+	assert(svc_mask == PSCI_FID_MASK);
+
+	return (uintptr_t)&psci_args;
+}
+
+/******************************************************************************
+ * The SP_MIN main function. Do the platform and PSCI Library setup. Also
+ * initialize the runtime service framework.
+ *****************************************************************************/
+void sp_min_main(void)
+{
 	NOTICE("SP_MIN: %s\n", version_string);
 	NOTICE("SP_MIN: %s\n", build_message);
 
 	/* Perform the SP_MIN platform setup */
 	sp_min_platform_setup();
 
-	/*
-	 * Initialize the PSCI library and perform the remaining generic
-	 * architectural setup from PSCI.
-	 */
-	psci_setup(&psci_args);
-
-	/*
-	 * Initialize the runtime services e.g. psci
-	 * This is where the monitor mode will be initialized
-	 */
+	/* Initialize the runtime services e.g. psci */
 	INFO("SP_MIN: Initializing runtime services\n");
 	runtime_svc_init();
 
diff --git a/include/services/std_svc.h b/include/services/std_svc.h
index 0feb2eae..38ce8bb4 100644
--- a/include/services/std_svc.h
+++ b/include/services/std_svc.h
@@ -42,4 +42,13 @@
 #define STD_SVC_VERSION_MAJOR		0x0
 #define STD_SVC_VERSION_MINOR		0x1
 
+/*
+ * Get the ARM Standard Service argument from EL3 Runtime.
+ * This function must be implemented by EL3 Runtime and the
+ * `svc_mask` identifies the service. `svc_mask` is a bit
+ * mask identifying the range of SMC function IDs available
+ * to the service.
+ */
+uintptr_t get_arm_std_svc_args(unsigned int svc_mask);
+
 #endif /* __STD_SVC_H__ */
diff --git a/services/std_svc/std_svc_setup.c b/services/std_svc/std_svc_setup.c
index 06647e00..e0966014 100644
--- a/services/std_svc/std_svc_setup.c
+++ b/services/std_svc/std_svc_setup.c
@@ -28,6 +28,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <assert.h>
 #include <debug.h>
 #include <psci.h>
 #include <runtime_svc.h>
@@ -41,6 +42,21 @@ DEFINE_SVC_UUID(arm_svc_uid,
 		0x108d905b, 0xf863, 0x47e8, 0xae, 0x2d,
 		0xc0, 0xfb, 0x56, 0x41, 0xf6, 0xe2);
 
+/* Setup Standard Services */
+static int32_t std_svc_setup(void)
+{
+	uintptr_t svc_arg;
+
+	svc_arg = get_arm_std_svc_args(PSCI_FID_MASK);
+	assert(svc_arg);
+
+	/*
+	 * PSCI is the only specification implemented as a Standard Service.
+	 * The `psci_setup()` also does EL3 architectural setup.
+	 */
+	return psci_setup((const psci_lib_args_t *)svc_arg);
+}
+
 /*
  * Top-level Standard Service SMC handler. This handler will in turn dispatch
  * calls to PSCI SMC handler
@@ -93,6 +109,6 @@ DECLARE_RT_SVC(
 		OEN_STD_START,
 		OEN_STD_END,
 		SMC_TYPE_FAST,
-		NULL,
+		std_svc_setup,
 		std_svc_smc_handler
 );